1. Field of the Invention
The present invention relates to a system for correcting vision by using a laser and a method thereof. More particularly, the present invention relates to an integrated corneal ablation system for correcting both shape and curvature of a cornea by creating a defective shape correction scheme of correcting a defective shape of an asymmetric cornea into a symmetric cornea that has a posterior corneal cone located at a central portion of the cornea through reducing thickness deviation in view of point symmetry to relieve eccentricity of the posterior corneal cone, and combining the defective shape correction scheme with a conventional vision correction scheme of removing a low-order aberration, and a method thereof.
2. Description of the Related Art
A laser vision correction technique is known as a conventional vision correction scheme for improving the visual acuity by cutting the cornea to remove its low-order aberration.
The laser vision correction technique is a scheme of setting all corneas as an ellipse, having a spherical or axial-symmetric shape, and cutting the cornea in order to eliminate the low order aberration (spherical aberration and astigmatism).
In addition, there is a scheme of measuring the focus dispersion due to shape distortion by a corneal topography or a fractography (front wave) tester, and cutting the cornea in a customized manner corresponding to a curvature error which is mutually different according to parts of the cornea. However, both schemes are schemes that remove only the measured curvature error while ignoring the imbalance of the intraocular pressure due to the thickness deviation to correct vision. Therefore, in the case of asymmetric corneas, it is impossible for both schemes to solve intricate problems such as corneal shape distortion and vision deterioration generated by the protrusion in a peripheral part of a posterior cornea due to the intraocular pressure after the corneal ablation for vision correction has been performed.